Discovery: method to handle dependency values

[mattfarina]

Dependencies may need to be configured in a manner to use non-default values. Sometimes a chart may need to ensure a feature is enabled on a shared dependency. The goal here is either to directly handle it or to provide direction for API users on how they can use the API to accomplish this. It may mean adjusting the Go API to make this possible.

This issue is a discovery ticket to work out a method to make this work. The output of this is technical detail on how to achieve this. A documentation or implementation ticket can be filed where appropriate.